Surgery Abx Prophylaxis Flashcards
What is a clean procedure?
Elective operative procedure does not enter:
- normally colonized viscus or
- lumen of the body.
Risk of infection of clean wound
- <2%
- Environmental contaminants
- Contaminants for surgical team
- Skin colonists; commonly Staph, aureus
What is a clean-contaminated procedure?
Elective operative procedure does enter:
- normally colonized viscus or
- lumen of the body.
Examples of clean-contaminated procedures
- Elective intestinal resection
- Pulmonary resection
- Gynecological
- Head-neck cancer operations that involve the oropharynx
Risk of infection of clean-contaminated wound
- <10%
- endogenous bacteria from site of surgery e.g. bowel - ecoli and mouth - anaerobes
- Can be optimized with specific preventive strategies.
What is a contaminated procedure?
When gross contamination is present at the surgical site in the absence of obvious infection.
Examples of contamined wound procedure
- Laparotomy for penetrating injury with intestinal spillage
- Elective intestinal procedures with gross contamination of the surgical site.
Risk of infection of contaminated wounds
- 20% even with preventative Abx
- Contaminants are the bacteria that are introduced by gross soilage of the surgical field.
What is a dirty wound procedure?
- Surgical procedures performed when active infection is already present
- Open injury
- Existing clinical infection
Examples of dirty wound procedures
- Abdominal exploration for acute bacterial peritonitis
- Intra-abdominal abscess are examples of this class of surgical site.
Risk of infection for dirty wounds
- 40%
Risk factors for surgical site infections
- Diabetes
- Corticosteroid use
- Obesity
- Extremes of age: with age healing takes longer
- Malnutrition
- Recent surgery
- Smoking
- Massive transfusion
- Immune deficiency states
- Renal/ liver impairment
- > 3 preop co-morbidities
- ASA class 3, 4 or 5
- Bacterial colonisation
Presence of 2 or more risk factors increases risk of infection for clean procedures 4-fold
Procedure risk factors
- Length of surgical scrub
- Lack of haemostasis
- Skin antisepsis
- Shaving
- Length of surgery
- Op theatre ventilation
- Surgical drains/ technique
Abx Prophylaxis
- 1st dose before skin incision is performed
- Ideally within 60 mins of time of incision
- When administered antibiotics within 2 hours of starting, operation infection rates have been shown to be 0.6% compared to 3.3% when given postoperatively
- Choice of regimen should be active against organisms most likely to cause infection
Deciding which Abx prophylaxis to give
Each NHS trust should have their own protocols for different surgery types based on:
- usual pathogens for the surgery type
- clinical trial comparison of different regimens
- local resistance patterns
